When performing gastro-intestinal (GI) endoscopy, it is typically desired to take tissue samples at the same time. This may be achieved by advancing an endoscopic biopsy instrument through the instrument-channel of a GI endoscope to take a tissue sample. In order to be able to do so, the endoscopic biopsy instrument has to fulfil very stringent conditions as to the dimensions and remote operability through a long and narrow instrument-channel. The instrument-channel is typically between 2-4 mm, or even between 1-2 mm in ultrathin endoscopes. At the same time, typical GI endoscopes have a length of about 1-2 m or even more. Furthermore when operated, the GI endoscope, and thus also the endoscopic biopsy instrument when inserted through the instrument channel, has to follow a long tortuous path through the gastro-intestinal tract in order to reach the site of investigation and sample-taking. An endoscopic biopsy instrument therefore has a functional device for taking tissue samples, which is located at a distal end of an elongate, flexible shaft. The functional device and a distal portion of the elongate flexible shaft are dimensioned and configured to be inserted into and follow the instrument channel. The functional device is remotely operable by means of operating controls located at a proximal end of the elongate, flexible shaft extending outside the endoscope (and thus outside the patient), wherein the operating controls communicate mechanically with the functional device through the elongate, flexible shaft. Typically, the operating controls are combined in an operating handle at the proximal end of the endoscopic biopsy instrument. The functional device is a biopsy device for taking tissue samples from a bodily cavity, more particular for taking tissue samples from the inside of the GI tract.
One problem of common biopsy instruments is that they have to be removed from the instrument channel after each biopsy in order to recover the tissue sample. This results in a time consuming procedure when several tissue samples have to be secured from the same site and/or different sites. In practice, this also limits the number of tissue samples that can be taken from a patient during a given endoscopic examination session, and may therefore require more than one session in order to obtain a sufficient number of tissue samples. Furthermore, the examination may require that a plurality of tissue samples be collected around the same location. When having to remove the biopsy instrument after each sample taking, it may be difficult to precisely control and map the exact location of each tissue sample, and of the different tissue samples with respect to each other.
This problem is addressed by endoscopic instruments for multiple sample biopsy that are adapted to collect multiple tissue samples without having to remove the instrument from the body between samples. WO 95/08945 discloses an endoscopic instrument for obtaining a series of multiple tissue samples without being withdrawn from the endoscope. The instrument comprises jaws that are operable to secure a tissue sample. In one aspect the instrument comprises a needle-shaped retractor constructed to accumulate a series of tissue samples. The retractor is operated to pierce a newly secured sample for picking up the sample. However, previously collected samples press against the new sample, thus affecting reliability of the pick-up.
A further problem of such endoscopic biopsy instruments that are intended for use in narrow instrument channels is to obtain a reliable remote operation, in particular when the endoscope is inserted into a body cavity along a tortuous path. Furthermore, the tough spatial constraints make it very difficult to implement more advanced/complex functionality that may require a plurality of wires and/or flexible push rods for the transmission of operation control forces to the functional device.
Object of the present invention is to provide an endoscopic biopsy device/instrument for securing and collecting multiple tissue samples that overcomes problems of the prior art, provides an improvement or at least an alternative.